The core of Manufacturing Grid (MG) is Manufacturing Resource (MR) sharing and collaboration, so the efficient discovery of sharable MRs is the precondition and basis that the resource sharing, collaborative design and manufacturing can be realized successfully in MG. Aiming at the problem that semantic information is represented insufficiently when MRs are searched in MG, we propose an ontology-based MR discovery architecture which is based on semantic web technology. Then from the point of view based on semantics and QoS (Quality of Service), the main framework of resource matchmaking is constructed, in which three processes are included: task modeling, resource modeling, semantic modeling and resource matchmaking. On the basis of resource representation model and manufacturing featuresoriented task representation model, combining with the research results of semantic web, some pivotal concepts are defined about the matchmaking resources. Finally, by means of a functional semantic extending method based on the ontology and QoS, the MR matchmaking algorithm is constructed.